React ERROR: Refs Must Have Owner

Warning: Element ref was specified as a string (myRefName) but no owner was set. You may have multiple copies of React loaded.

This usually means one of two things:

• You are trying to add a ref to an element that is being created outside of a component’s render() function.
• You have multiple (conflicting) copies of React loaded (eg. due to a misconfigured npm dependency)

报错实例：

function(){
   render(
        <div className="u-toast-fixed" >
          <div className="u-toast-content" ref="tip">
            {text}
          </div>
        </div>
    )

}

改善方式：

function(){
   render(
        <div className="u-toast-fixed" >
          <div className="u-toast-content" ref={c=>this.utip = c}>
            {text}
          </div>
        </div>
    )

}